Background: Current methods of renal replacement therapy lead only to an insignificant removal of larger, potentially toxic, substances, which are excreted by healthy kidneys. On-line preparation of substitute from dialysate and the use of high-flux membranes allow substantial convective removal of such substances.Objectives: to demonstrate that the dialytic removal of β2-microglobulin using on-line hemodiafiltration is more than conventional low flux hemodialysis and superior to it, thus decreasing the incidence of DRA (dialysis related amyloidosis) and the related complications. Methods: This study will include 32 pediatric patients below 16 years of age with end stage renal disease on maintenance hemodialysis 3 times/week, 4 hours per session, at the Centre of Pediatric Nephrology and Transplantation, Cairo University. These patients divided into two groups, study group (16 patients on on-line HDF) and control group (16 patients on conventional low flux hemodialysis). B2-microglobulin was measured for all patients before and after dialysis session, then after 3 months of dialysis before session & compared with the previously measured ones. The results of this study showed that the on-line HDF is superior in removing of B2-M than the conventional HD.